diff options
Diffstat (limited to 'Documentation/git-rev-parse.txt')
| -rw-r--r-- | Documentation/git-rev-parse.txt | 579 |
1 files changed, 366 insertions, 213 deletions
diff --git a/Documentation/git-rev-parse.txt b/Documentation/git-rev-parse.txt index ccc66aae7f..b6c6326cdc 100644 --- a/Documentation/git-rev-parse.txt +++ b/Documentation/git-rev-parse.txt @@ -8,28 +8,62 @@ git-rev-parse - Pick out and massage parameters SYNOPSIS -------- -'git-rev-parse' [ --option ] <args>... +[verse] +'git rev-parse' [ --option ] <args>... DESCRIPTION ----------- -Many git porcelainish commands take mixture of flags +Many Git porcelainish commands take mixture of flags (i.e. parameters that begin with a dash '-') and parameters -meant for underlying `git-rev-list` command they use internally -and flags and parameters for other commands they use as the -downstream of `git-rev-list`. This command is used to +meant for the underlying 'git rev-list' command they use internally +and flags and parameters for the other commands they use +downstream of 'git rev-list'. This command is used to distinguish between them. OPTIONS ------- + +Operation Modes +~~~~~~~~~~~~~~~ + +Each of these options must appear first on the command line. + +--parseopt:: + Use 'git rev-parse' in option parsing mode (see PARSEOPT section below). + +--sq-quote:: + Use 'git rev-parse' in shell quoting mode (see SQ-QUOTE + section below). In contrast to the `--sq` option below, this + mode does only quoting. Nothing else is done to command input. + +Options for --parseopt +~~~~~~~~~~~~~~~~~~~~~~ + +--keep-dashdash:: + Only meaningful in `--parseopt` mode. Tells the option parser to echo + out the first `--` met instead of skipping it. + +--stop-at-non-option:: + Only meaningful in `--parseopt` mode. Lets the option parser stop at + the first non-option argument. This can be used to parse sub-commands + that take options themselves. + +--stuck-long:: + Only meaningful in `--parseopt` mode. Output the options in their + long form if available, and with their arguments stuck. + +Options for Filtering +~~~~~~~~~~~~~~~~~~~~~ + --revs-only:: Do not output flags and parameters not meant for - `git-rev-list` command. + 'git rev-list' command. --no-revs:: Do not output flags and parameters meant for - `git-rev-list` command. + 'git rev-list' command. --flags:: Do not output non-flag parameters. @@ -37,13 +71,50 @@ OPTIONS --no-flags:: Do not output flag parameters. +Options for Output +~~~~~~~~~~~~~~~~~~ + --default <arg>:: If there is no parameter given by the user, use `<arg>` instead. +--prefix <arg>:: + Behave as if 'git rev-parse' was invoked from the `<arg>` + subdirectory of the working tree. Any relative filenames are + resolved as if they are prefixed by `<arg>` and will be printed + in that form. ++ +This can be used to convert arguments to a command run in a subdirectory +so that they can still be used after moving to the top-level of the +repository. For example: ++ +---- +prefix=$(git rev-parse --show-prefix) +cd "$(git rev-parse --show-toplevel)" +eval "set -- $(git rev-parse --sq --prefix "$prefix" "$@")" +---- + --verify:: - The parameter given must be usable as a single, valid - object name. Otherwise barf and abort. + Verify that exactly one parameter is provided, and that it + can be turned into a raw 20-byte SHA-1 that can be used to + access the object database. If so, emit it to the standard + output; otherwise, error out. ++ +If you want to make sure that the output actually names an object in +your object database and/or can be used as a specific type of object +you require, you can add the `^{type}` peeling operator to the parameter. +For example, `git rev-parse "$VAR^{commit}"` will make sure `$VAR` +names an existing object that is a commit-ish (i.e. a commit, or an +annotated tag that points at a commit). To make sure that `$VAR` +names an existing object of any type, `git rev-parse "$VAR^{object}"` +can be used. + +-q:: +--quiet:: + Only meaningful in `--verify` mode. Do not output an error + message if the first argument is not a valid object name; + instead exit with non-zero status silently. + SHA-1s for valid object names are printed to stdout on success. --sq:: Usually the output is made one line per flag and @@ -51,239 +122,321 @@ OPTIONS properly quoted for consumption by shell. Useful when you expect your parameter to contain whitespaces and newlines (e.g. when using pickaxe `-S` with - `git-diff-\*`). + 'git diff-{asterisk}'). In contrast to the `--sq-quote` option, + the command input is still interpreted as usual. --not:: When showing object names, prefix them with '{caret}' and strip '{caret}' prefix from the object names that already have one. +--abbrev-ref[=(strict|loose)]:: + A non-ambiguous short name of the objects name. + The option core.warnAmbiguousRefs is used to select the strict + abbreviation mode. + +--short:: +--short=number:: + Instead of outputting the full SHA-1 values of object names try to + abbreviate them to a shorter unique name. When no length is specified + 7 is used. The minimum length is 4. + --symbolic:: - Usually the object names are output in SHA1 form (with + Usually the object names are output in SHA-1 form (with possible '{caret}' prefix); this option makes them output in a form as close to the original input as possible. +--symbolic-full-name:: + This is similar to --symbolic, but it omits input that + are not refs (i.e. branch or tag names; or more + explicitly disambiguating "heads/master" form, when you + want to name the "master" branch when there is an + unfortunately named tag "master"), and show them as full + refnames (e.g. "refs/heads/master"). ---all:: - Show all refs found in `$GIT_DIR/refs`. +Options for Objects +~~~~~~~~~~~~~~~~~~~ ---branches:: - Show branch refs found in `$GIT_DIR/refs/heads`. +--all:: + Show all refs found in `refs/`. + +--branches[=pattern]:: +--tags[=pattern]:: +--remotes[=pattern]:: + Show all branches, tags, or remote-tracking branches, + respectively (i.e., refs found in `refs/heads`, + `refs/tags`, or `refs/remotes`, respectively). ++ +If a `pattern` is given, only refs matching the given shell glob are +shown. If the pattern does not contain a globbing character (`?`, +`*`, or `[`), it is turned into a prefix match by appending `/*`. + +--glob=pattern:: + Show all refs matching the shell glob pattern `pattern`. If + the pattern does not start with `refs/`, this is automatically + prepended. If the pattern does not contain a globbing + character (`?`, `*`, or `[`), it is turned into a prefix + match by appending `/*`. + +--exclude=<glob-pattern>:: + Do not include refs matching '<glob-pattern>' that the next `--all`, + `--branches`, `--tags`, `--remotes`, or `--glob` would otherwise + consider. Repetitions of this option accumulate exclusion patterns + up to the next `--all`, `--branches`, `--tags`, `--remotes`, or + `--glob` option (other options or arguments do not clear + accumulated patterns). ++ +The patterns given should not begin with `refs/heads`, `refs/tags`, or +`refs/remotes` when applied to `--branches`, `--tags`, or `--remotes`, +respectively, and they must begin with `refs/` when applied to `--glob` +or `--all`. If a trailing '/{asterisk}' is intended, it must be given +explicitly. + +--disambiguate=<prefix>:: + Show every object whose name begins with the given prefix. + The <prefix> must be at least 4 hexadecimal digits long to + avoid listing each and every object in the repository by + mistake. + +Options for Files +~~~~~~~~~~~~~~~~~ + +--local-env-vars:: + List the GIT_* environment variables that are local to the + repository (e.g. GIT_DIR or GIT_WORK_TREE, but not GIT_EDITOR). + Only the names of the variables are listed, not their value, + even if they are set. ---tags:: - Show tag refs found in `$GIT_DIR/refs/tags`. +--git-dir:: + Show `$GIT_DIR` if defined. Otherwise show the path to + the .git directory. The path shown, when relative, is + relative to the current working directory. ++ +If `$GIT_DIR` is not defined and the current directory +is not detected to lie in a Git repository or work tree +print a message to stderr and exit with nonzero status. + +--git-common-dir:: + Show `$GIT_COMMON_DIR` if defined, else `$GIT_DIR`. + +--is-inside-git-dir:: + When the current working directory is below the repository + directory print "true", otherwise "false". + +--is-inside-work-tree:: + When the current working directory is inside the work tree of the + repository print "true", otherwise "false". + +--is-bare-repository:: + When the repository is bare print "true", otherwise "false". + +--resolve-git-dir <path>:: + Check if <path> is a valid repository or a gitfile that + points at a valid repository, and print the location of the + repository. If <path> is a gitfile then the resolved path + to the real repository is printed. + +--git-path <path>:: + Resolve "$GIT_DIR/<path>" and takes other path relocation + variables such as $GIT_OBJECT_DIRECTORY, + $GIT_INDEX_FILE... into account. For example, if + $GIT_OBJECT_DIRECTORY is set to /foo/bar then "git rev-parse + --git-path objects/abc" returns /foo/bar/abc. ---remotes:: - Show tag refs found in `$GIT_DIR/refs/remotes`. +--show-cdup:: + When the command is invoked from a subdirectory, show the + path of the top-level directory relative to the current + directory (typically a sequence of "../", or an empty string). --show-prefix:: When the command is invoked from a subdirectory, show the path of the current directory relative to the top-level directory. ---show-cdup:: - When the command is invoked from a subdirectory, show the - path of the top-level directory relative to the current - directory (typically a sequence of "../", or an empty string). +--show-toplevel:: + Show the absolute path of the top-level directory. ---git-dir:: - Show `$GIT_DIR` if defined else show the path to the .git directory. +--shared-index-path:: + Show the path to the shared index file in split index mode, or + empty if not in split-index mode. ---short, --short=number:: - Instead of outputting the full SHA1 values of object names try to - abbreviate them to a shorter unique name. When no length is specified - 7 is used. The minimum length is 4. +Other Options +~~~~~~~~~~~~~ ---since=datestring, --after=datestring:: - Parses the date string, and outputs corresponding - --max-age= parameter for git-rev-list command. +--since=datestring:: +--after=datestring:: + Parse the date string, and output the corresponding + --max-age= parameter for 'git rev-list'. ---until=datestring, --before=datestring:: - Parses the date string, and outputs corresponding - --min-age= parameter for git-rev-list command. +--until=datestring:: +--before=datestring:: + Parse the date string, and output the corresponding + --min-age= parameter for 'git rev-list'. <args>...:: Flags and parameters to be parsed. -SPECIFYING REVISIONS --------------------- - -A revision parameter typically, but not necessarily, names a -commit object. They use what is called an 'extended SHA1' -syntax. Here are various ways to spell object names. The -ones listed near the end of this list are to name trees and -blobs contained in a commit. - -* The full SHA1 object name (40-byte hexadecimal string), or - a substring of such that is unique within the repository. - E.g. dae86e1950b1277e545cee180551750029cfe735 and dae86e both - name the same commit object if there are no other object in - your repository whose object name starts with dae86e. - -* An output from `git-describe`; i.e. a closest tag, followed by a - dash, a `g`, and an abbreviated object name. - -* A symbolic ref name. E.g. 'master' typically means the commit - object referenced by $GIT_DIR/refs/heads/master. If you - happen to have both heads/master and tags/master, you can - explicitly say 'heads/master' to tell git which one you mean. - When ambiguous, a `<name>` is disambiguated by taking the - first match in the following rules: - - . if `$GIT_DIR/<name>` exists, that is what you mean (this is usually - useful only for `HEAD`, `FETCH_HEAD` and `MERGE_HEAD`); - - . otherwise, `$GIT_DIR/refs/<name>` if exists; - - . otherwise, `$GIT_DIR/refs/tags/<name>` if exists; - - . otherwise, `$GIT_DIR/refs/heads/<name>` if exists; - - . otherwise, `$GIT_DIR/refs/remotes/<name>` if exists; - - . otherwise, `$GIT_DIR/refs/remotes/<name>/HEAD` if exists. - -* A ref followed by the suffix '@' with a date specification - enclosed in a brace - pair (e.g. '\{yesterday\}', '\{1 month 2 weeks 3 days 1 hour 1 - second ago\}' or '\{1979-02-26 18:30:00\}') to specify the value - of the ref at a prior point in time. This suffix may only be - used immediately following a ref name and the ref must have an - existing log ($GIT_DIR/logs/<ref>). - -* A ref followed by the suffix '@' with an ordinal specification - enclosed in a brace pair (e.g. '\{1\}', '\{15\}') to specify - the n-th prior value of that ref. For example 'master@\{1\}' - is the immediate prior value of 'master' while 'master@\{5\}' - is the 5th prior value of 'master'. This suffix may only be used - immediately following a ref name and the ref must have an existing - log ($GIT_DIR/logs/<ref>). - -* You can use the '@' construct with an empty ref part to get at a - reflog of the current branch. For example, if you are on the - branch 'blabla', then '@\{1\}' means the same as 'blabla@\{1\}'. - -* A suffix '{caret}' to a revision parameter means the first parent of - that commit object. '{caret}<n>' means the <n>th parent (i.e. - 'rev{caret}' - is equivalent to 'rev{caret}1'). As a special rule, - 'rev{caret}0' means the commit itself and is used when 'rev' is the - object name of a tag object that refers to a commit object. - -* A suffix '{tilde}<n>' to a revision parameter means the commit - object that is the <n>th generation grand-parent of the named - commit object, following only the first parent. I.e. rev~3 is - equivalent to rev{caret}{caret}{caret} which is equivalent to - rev{caret}1{caret}1{caret}1. See below for a illustration of - the usage of this form. - -* A suffix '{caret}' followed by an object type name enclosed in - brace pair (e.g. `v0.99.8{caret}\{commit\}`) means the object - could be a tag, and dereference the tag recursively until an - object of that type is found or the object cannot be - dereferenced anymore (in which case, barf). `rev{caret}0` - introduced earlier is a short-hand for `rev{caret}\{commit\}`. - -* A suffix '{caret}' followed by an empty brace pair - (e.g. `v0.99.8{caret}\{\}`) means the object could be a tag, - and dereference the tag recursively until a non-tag object is - found. - -* A colon, followed by a slash, followed by a text: this names - a commit whose commit message starts with the specified text. - This name returns the youngest matching commit which is - reachable from any ref. If the commit message starts with a - '!', you have to repeat that; the special sequence ':/!', - followed by something else than '!' is reserved for now. - -* A suffix ':' followed by a path; this names the blob or tree - at the given path in the tree-ish object named by the part - before the colon. - -* A colon, optionally followed by a stage number (0 to 3) and a - colon, followed by a path; this names a blob object in the - index at the given path. Missing stage number (and the colon - that follows it) names an stage 0 entry. - -Here is an illustration, by Jon Loeliger. Both node B and C are -a commit parents of commit node A. Parent commits are ordered -left-to-right. - - G H I J - \ / \ / - D E F - \ | / \ - \ | / | - \|/ | - B C - \ / - \ / - A - - A = = A^0 - B = A^ = A^1 = A~1 - C = A^2 = A^2 - D = A^^ = A^1^1 = A~2 - E = B^2 = A^^2 - F = B^3 = A^^3 - G = A^^^ = A^1^1^1 = A~3 - H = D^2 = B^^2 = A^^^2 = A~2^2 - I = F^ = B^3^ = A^^3^ - J = F^2 = B^3^2 = A^^3^2 - - -SPECIFYING RANGES ------------------ - -History traversing commands such as `git-log` operate on a set -of commits, not just a single commit. To these commands, -specifying a single revision with the notation described in the -previous section means the set of commits reachable from that -commit, following the commit ancestry chain. - -To exclude commits reachable from a commit, a prefix `{caret}` -notation is used. E.g. "`{caret}r1 r2`" means commits reachable -from `r2` but exclude the ones reachable from `r1`. - -This set operation appears so often that there is a shorthand -for it. "`r1..r2`" is equivalent to "`{caret}r1 r2`". It is -the difference of two sets (subtract the set of commits -reachable from `r1` from the set of commits reachable from -`r2`). - -A similar notation "`r1\...r2`" is called symmetric difference -of `r1` and `r2` and is defined as -"`r1 r2 --not $(git-merge-base --all r1 r2)`". -It it the set of commits that are reachable from either one of -`r1` or `r2` but not from both. - -Two other shorthands for naming a set that is formed by a commit -and its parent commits exists. `r1{caret}@` notation means all -parents of `r1`. `r1{caret}!` includes commit `r1` but excludes -its all parents. - -Here are a handful examples: - - D A B D - D F A B C D F - ^A G B D - ^A F B C F - G...I C D F G I - ^B G I C D F G I - F^@ A B C - F^! H D F H - -Author ------- -Written by Linus Torvalds <torvalds@osdl.org> and -Junio C Hamano <junkio@cox.net> - -Documentation --------------- -Documentation by Junio C Hamano and the git-list <git@vger.kernel.org>. +include::revisions.txt[] + +PARSEOPT +-------- + +In `--parseopt` mode, 'git rev-parse' helps massaging options to bring to shell +scripts the same facilities C builtins have. It works as an option normalizer +(e.g. splits single switches aggregate values), a bit like `getopt(1)` does. + +It takes on the standard input the specification of the options to parse and +understand, and echoes on the standard output a string suitable for `sh(1)` `eval` +to replace the arguments with normalized ones. In case of error, it outputs +usage on the standard error stream, and exits with code 129. + +Note: Make sure you quote the result when passing it to `eval`. See +below for an example. + +Input Format +~~~~~~~~~~~~ + +'git rev-parse --parseopt' input format is fully text based. It has two parts, +separated by a line that contains only `--`. The lines before the separator +(should be one or more) are used for the usage. +The lines after the separator describe the options. + +Each line of options has this format: + +------------ +<opt-spec><flags>*<arg-hint>? SP+ help LF +------------ + +`<opt-spec>`:: + its format is the short option character, then the long option name + separated by a comma. Both parts are not required, though at least one + is necessary. May not contain any of the `<flags>` characters. + `h,help`, `dry-run` and `f` are examples of correct `<opt-spec>`. + +`<flags>`:: + `<flags>` are of `*`, `=`, `?` or `!`. + * Use `=` if the option takes an argument. + + * Use `?` to mean that the option takes an optional argument. You + probably want to use the `--stuck-long` mode to be able to + unambiguously parse the optional argument. + + * Use `*` to mean that this option should not be listed in the usage + generated for the `-h` argument. It's shown for `--help-all` as + documented in linkgit:gitcli[7]. + + * Use `!` to not make the corresponding negated long option available. + +`<arg-hint>`:: + `<arg-hint>`, if specified, is used as a name of the argument in the + help output, for options that take arguments. `<arg-hint>` is + terminated by the first whitespace. It is customary to use a + dash to separate words in a multi-word argument hint. + +The remainder of the line, after stripping the spaces, is used +as the help associated to the option. + +Blank lines are ignored, and lines that don't match this specification are used +as option group headers (start the line with a space to create such +lines on purpose). + +Example +~~~~~~~ + +------------ +OPTS_SPEC="\ +some-command [options] <args>... + +some-command does foo and bar! +-- +h,help show the help + +foo some nifty option --foo +bar= some cool option --bar with an argument +baz=arg another cool option --baz with a named argument +qux?path qux may take a path argument but has meaning by itself + + An option group Header +C? option C with an optional argument" + +eval "$(echo "$OPTS_SPEC" | git rev-parse --parseopt -- "$@" || echo exit $?)" +------------ + + +Usage text +~~~~~~~~~~ + +When `"$@"` is `-h` or `--help` in the above example, the following +usage text would be shown: + +------------ +usage: some-command [options] <args>... + + some-command does foo and bar! + + -h, --help show the help + --foo some nifty option --foo + --bar ... some cool option --bar with an argument + --baz <arg> another cool option --baz with a named argument + --qux[=<path>] qux may take a path argument but has meaning by itself + +An option group Header + -C[...] option C with an optional argument +------------ + +SQ-QUOTE +-------- + +In `--sq-quote` mode, 'git rev-parse' echoes on the standard output a +single line suitable for `sh(1)` `eval`. This line is made by +normalizing the arguments following `--sq-quote`. Nothing other than +quoting the arguments is done. + +If you want command input to still be interpreted as usual by +'git rev-parse' before the output is shell quoted, see the `--sq` +option. + +Example +~~~~~~~ + +------------ +$ cat >your-git-script.sh <<\EOF +#!/bin/sh +args=$(git rev-parse --sq-quote "$@") # quote user-supplied arguments +command="git frotz -n24 $args" # and use it inside a handcrafted + # command line +eval "$command" +EOF + +$ sh your-git-script.sh "a b'c" +------------ + +EXAMPLES +-------- + +* Print the object name of the current commit: ++ +------------ +$ git rev-parse --verify HEAD +------------ + +* Print the commit object name from the revision in the $REV shell variable: ++ +------------ +$ git rev-parse --verify $REV^{commit} +------------ ++ +This will error out if $REV is empty or not a valid revision. + +* Similar to above: ++ +------------ +$ git rev-parse --default master --verify $REV +------------ ++ +but if $REV is empty, the commit object name from master will be printed. GIT --- -Part of the gitlink:git[7] suite - +Part of the linkgit:git[1] suite |